1. Field of the Invention
The present invention relates to a refrigerator, and more particularly to an automatic ice maker of a refrigerator.
2. Description of the Prior Art
Generally, a refrigerator includes a freezing compartment, a refrigerating compartment and an ice-making compartment. A cool air cooled by a cooler is distributed to each compartment by a cooling fan. The freezing compartment stores the foodstuffs to be frozen, the refrigerating compartment stores the foodstuffs at a lower temperature, and the ice-making compartment makes the ice by freezing the water. An ice maker for freezing the water is installed in the ice-making compartment. The ice-maker is an apparatus for making an ice, in which the water is supplied to an ice-making container and then the water is frozen therein, thereby discharging the ices by overturning the ice-making container by a driving apparatus.
The ice maker is disclosed in a U.S. Pat. No. 5,177,980(issued to Akira Kawamoto et al.) and a U.S. Pat. No. 5,400,605(issued to Sung-Ki Jeong).
As illustrated in FIG. 1, an automatic ice maker of refrigerator 100 comprises a motor 110 for generating a driving force accommodated in a body 105, a gear assembly 120 for transmitting the driving force generated by the motor 110, an ice-making container 130 rotatably coupled to the gear assembly 120, an ice cube storage bin 150 for storing the ice cubes discharged from the ice-making container 130 and a sensing lever 160 for sensing an amount of the ice stored in the ice cube storage bin.
The motor 110 is accommodated in the body 105 by a plurality of fixing members 116, and a worm gear 114 is integrally formed at an end portion of a rotating shaft 112 of the motor 110. The driving force generated by the motor 110 is transmitted to the gear assembly 120 through the worm gear 114. The gear assembly 120 comprises a worm wheel gear 122, a first spur gear 124, a second spur gear 126 and a driving gear 128. The worm wheel gear 122 is meshed with the worm gear 114 of the motor 110, and the first gear 123 having a smaller diameter than the diameter of the worm wheel gear 122 is fixedly coupled to a central shaft of the worm wheel gear 122. The first spur gear 124 is meshed with the first gear 123, and a second gear 125 having a smaller diameter than the diameter of the first spur gear 124 is coupled to the central shaft of the first spur gear 124. The second spur gear 126 is meshed with the second gear 125, and a third gear 127 having a smaller diameter than the diameter of the second spur gear 126 is fixedly coupled to the central shaft of the second spur gear 126. Finally, the third gear 127 is meshed with the driving gear 128. The driving gear 128 is formed at a center thereof with a central shaft 121. The central shaft 121 is inserted into a rectangular-shaped groove 138 formed at an end portion of the ice-making container 130. The central shaft 121 has a rectangular shape for preventing the ice-making container from sliding while the ice-making container 130 is being rotated.
Also, the ice-making container 130 is rotatably coupled to a fixing plate 132 integrally formed at a side portion of the body 105. The ice-making container 130 is a vessel having a concave shape for storing the supplied water, and a concave portion 137 is divided by a compartment. A circular shaft 134 is protrudingly formed at a first side portion of the ice-making container 130, and the circular shaft 134 is rotatably inserted into a circular groove 136 formed at a side surface of the fixing plate 132. The ice-making container is formed with a rectangular-shaped groove 138 at a second side surface thereof, into which the connecting shaft 121 of the driving gear 128 is inserted.
A cam 129 is inserted into the connecting shaft 121 of the driving gear 128, and an end portion of the sensing lever 160 makes contact with the cam 129. The sensing lever 160 has a first end portion for making contact with the cam 129, a second end portion having a bending portion which is downwardly bent, and a middle portion positioned between the first end portion and the second end portion, and is formed with a pivot hole 166 through which a pivot pin 168 is penetrated, for pivotally fixing the sensing lever 160 to the body 105. The bending portion 164 of the sensing lever 164 is positioned in the ice cube storage bin 150 for sensing an amount of the ice cubes. A limit switch 140 is positioned at an upper portion of the sensing lever 160 for making contact with the sensing lever 160.
When electric power is transmitted to the motor 110, the motor 110 is rotated, so the worm wheel gear 122 meshed with the worm gear 114 of the motor 110 is rotated. Accordingly, the driving force is transmitted to the driving gear 128 through the first gear 124 meshed with the worm wheel gear 122 and through the second gear 126 meshed with the first gear 124. When the ice-making container 130 is being rotated in a clock-wise direction, the ice cubes are discharged from the ice-making container 130, so the ice cubes are stored in the ice cube storage bin 150 disposed beneath the ice-making container 130.
In addition, the cam 129 makes contact with the sensing lever 160 by means of the rotation of the driving gear 128. Accordingly, the end portion of the sensing lever 160 is downwardly moved and the other end portion of the sensing lever 160 is upwardly moved, so the end portion of the sensing lever makes contact with a terminal of the limit switch 140. Then, a signal of the limit switch is sent to a control unit and the motor 110 is reversely rotated. By a reverse rotation of the motor 110, the driving force is reversely transmitted to the ice-making container 130 with respect to the transmission described above, and the ice-making container finishes discharging the ice cubes and is returned to an initial position.
However, in the conventional automatic ice maker for a refrigerator, since the ice maker controls the motor by one limit switch, a malfunction thereof occurs frequently. Furthermore, since the power is only transmitted by the gear assembly, it is difficult to control the power transmission.